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| Titel |
Impact of afforestation on peroxidase activity and iron ions in soils |
| VerfasserIn |
T. Meysner, L. Szajdak |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250020889
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| Zusammenfassung |
| Oxidation-reduction reactions play a key role in ecologically important biogeochemical
processes in soil and influence on soil chemical and physical properties. For understanding of
processes in soil system the direction of oxidation and reduction processes is needed.
Researches were carried out in the afforestation as biogeochemical barrier and adjoining
cultivated field located in the Agroecological Landscape Park in Turew (40 km south of
Poznań, West Polish Lowland). This afforestation was created approximately 200 years ago
and includes mainly of Robinia pseudacacia. It is 2 kilometres long and 36 meters wide. The
accumulation of organic matter level achieves a depth of 15 cm. Times of sampling were
collected from June to November in 2008 from the layer at 0-20 cm depth. Five soil
samples from each site were pooled together to give the so-called average mixed
sample.
The peroxidase activity in soils was determined by Bartha and Bordeleau method, ferrous
ions by phenanthroline and ferric ions by thiocyanate method. The dissolved organic carbon
and a total organic carbon were estimated using analyzer TOC-5050A facilities, Solid Sample
Module SSM-5000A, Shimadzu, Japan.
As is well known, the role of enzymes in coupling reactions leading to polymerization is
limited to the oxidation of the substrates. Peroxidase catalyzes the oxidation of phenols and
aromatic amines in the presence of hydrogen peroxide as an electron acceptor in the
reactions. This study showed that the peroxidase activities were higher in the soils
under afforestation (from 14.16⋅10-4 to 126.16⋅10-4μmol⋅h-1⋅g-1) than under
cultivated field (from 0.76⋅10-4 to 2.75⋅10-4μmol⋅h-1⋅g-1) during whole period of
sampling.
Its many chemical conversions are due to its two valence states, ferrous and ferric ions as
well as the range of oxidation-reduction potentials associated with transition in various
iron-containing compounds. It was observed that the concentrations of total iron ranged from
7.78 to 17.96 mg⋅kg-1 in the soils under afforestation and from 2.48 to 10.98 mg⋅kg-1
in the soils under cultivated field. This investigation revealed that the content of
ferrous ions (from 1 to 64%) and ferric ions (from 3 to 71%) was higher in the soils
under afforestation than in the soils under cultivated field in the most periods of
sampling.
Dissolved organic matter in soil solutions plays a crucial role as a carrier for a
variety of components, ranging from nutrients and trace elements to toxics. The soils
under cultivated field resulted in a lower concentrations of dissolved organic carbon
(from 0.34 to 0.52 g⋅kg-1) then the soils under afforestation (from 1.11 to 3.39
g⋅kg-1).
It is known that although soil organic matter only tends to form a small percentage of the
mass of the soil, it has a very great influence on soil chemical and physical properties. Our
results showed that the total organic carbon concentration ranged from 19.82 to 65.16
g⋅kg-1in the soils under afforestation and from 5.50 to 7.04 g⋅kg-1 in the soils under
cultivated field. |
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